Feb. 12 (Bloomberg) -- Taking folic acid supplements in
early pregnancy was linked to a lower risk of autistic disorder
in children in a study, suggesting the nutrient already
recommended for mothers-to-be may carry an additional benefit.

Mothers who took the supplements 4 weeks to 8 weeks after
the start of pregnancy were 39 percent less likely to have
children with autism, compared with mothers who didn’t take
folic acid, according to the study. Researchers followed more
than 85,000 babies born in Norway between 2002 and 2008 for as
long as 10 years.

“There was a dramatic reduction in the risk of autistic
disorder in children born to mothers who took folic acid
supplements,” said Pal Suren, one of the authors of the study
and an epidemiologist at the Norwegian Institute of Public
Health. The finding doesn’t prove that folic acid itself reduced
the autism risk, the researchers said. The study will be
published tomorrow in the Journal of the American Medical
Association.

Folic acid is needed to fuse the spinal cord in early fetal
development, preventing neural tube defects such as spina
bifida. The nutrient, found naturally in foods such as broccoli,
liver and spinach, was associated with a reduced risk of severe
language delays in children of mothers who took it, according to
a study by the same Norwegian group of researchers that JAMA
published in 2011. Folic acid may also prevent cleft lip, a
birth defect, a 2007 British Medical Journal study found.

Autism Spectrum

About 1 in 88 children in the U.S. are diagnosed with an
autism-related condition. The disorder interferes with brain
development and is linked to poor social interaction and
communication skills, repeated body movements, and unusual
attachments to objects. Autistic disorder, which has no known
cause or cure, is the most severe form of neurodevelopmental
conditions grouped as autism spectrum disorders.

Of the thousands of babies tracked by the researchers, 270
children had been diagnosed with an autism spectrum disorder. No
statistically significant links were found between folic acid
consumption and the risk of Asperger syndrome or other types of
autism. No association was found between the mother’s use of
fish oil supplements or other vitamins and minerals and autism
rates, the researchers said.

The study was funded by the Norwegian government and the
U.S. National Institutes of Health.

In Norway, the U.K. and the U.S., a daily dose of 400
micrograms is recommended through the first trimester of
pregnancy. Folic acid has been used to fortify flour and grains
in the U.S. and other countries for the past decade because it
reduces spinal-cord defects.

“The potential for a nutritional supplement to reduce the
risk of autistic disorder is provocative and should be confirmed
in other populations,” Robert Berry, Krista Crider and
Marshalyn Yeargin-Allsopp of the U.S. Centers for Disease
Control and Prevention in Atlanta, said in a comment
accompanying the paper. “Future studies should include other
populations with different diets, recommendations for folic acid
supplementation and voluntary and mandatory enriched cereal
grain fortification programs.”